1. Field of the Invention
The present invention relates generally to a computer implemented method, data processing system, and computer program product for conserving free disk space in data processing systems having a file encrypted with a first key and a file encrypted with a second key. More specifically, the present invention relates to selectively deleting encrypted files based on a key associated with a user session and at least one key associated with the encrypted files.
2. Description of the Related Art
Distribution of executable files and data can performed in a manner that reduces the transport and storage costs of the set of files. The set, sometimes called a distribution, package or a release, can occupy considerably less space if compressed. A manufacturer of such a package may provide features and data that are available on a tiered basis. For example, a version of the distribution may provide functions for an entry-level purchaser of the distribution. Another version of the distribution may provide functions for an advanced purchaser of the distribution. The component files of each package may be encrypted with a public key of one or more users, so that a subset of functionality in the package is available to be decrypted by each user.
Each version of the distribution may be available in an archive, for example a tape archive (TAR). Unfortunately, the archive may have many files that a particular user cannot extract since files are encrypted with keys not associated with the user. This feature of TARs can make embedded files useless with respect to the user. Consequently, the useless files can occupy space on a file system with no attendant benefit.
It would be helpful to eliminate useless files from an archive prior to de-compressing or extracting the files of the archive.